Fastening mechanism for medical connectors

ABSTRACT

A medical connector adapted for placement between a catheter and a medical infusion or injection source includes a pair of interlocking half medical connector portions, one side of which attaches to the infusion source and the other side of which is coupled to the catheter connected to the patient and a locking mechanism for locking a medical connector portion to a medical fitting. The connection to the catheter and the infusion source can be via standard medical luer taper fittings, with or without specially designed locking mechanisms that prevent inadvertent disconnection. The medical connector itself is uniquely shaped and includes a raised surface feature and a recessed surface feature formed on the medical connector portions.

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 09/094,433, filed Jun. 8, 1998, entitled “Safety IndexedMedical Connectors”, now U.S. Pat. No. 6,402,207 the contents of whichare herein incorporated by reference.

BACKGROUND OF THE INVENTION

The present invention relates to fluid connectors, and more particularlyto fluid connectors used in medical environments and designed to ensurethe correct and appropriate administration of medicaments to a patient.

Errors in prescribing and delivering medications to patients are,unfortunately, common in medical practice. Many of these mistakes resultin patient injury or death, and even if the patient recovers fully, thecost to society of induced and prolonged hospital stays and greaterpatient charges are staggering. It is estimated that at least 25,000incidents involving drugs administered to a patient by the wrong routeoccur annually, all of which are the result of preventable human error.The most common cause of confusion in route of administration is theuniversal nature of medical connectors and injection sites. Most medicalconnectors and infusion/injection sites are universal couplers that aredesigned to mate with and therefore accept most syringes and other fluiddelivering devices. The most common types of infusion sites are rubbersepta designed to be pierced by a needle, and female luer connectorsdesigned to be connected to a syringe or medical tubing with a male luerfitting, either by friction fit or threaded lock. Both types of sitesare commonly included in intravenous infusion tubing, on the ends ofheparin locks, in stopcocks in all types of intravenous, arterial,epidural, and other type connectors, and even in devices not designedfor medication or fluid infusion at all, such as esophageal stethoscopesand urinary catheters. The universal employment of rubber septuminjection ports and female luer connectors is directly coupled tothousands of errors in which a medication or fluid designed to be givenby one route has inadvertently been given by another route, sometimeswith disastrous consequences.

Several additional problems arise from use of current technology. Theuse of needles for connecting infusion lines and the administration ofmedicines has led to many cases of needlestick injury and transmissionof blood borne infections, including hepatitis and AIDS. The infusion ofproper fluids through the needle and coupler is also prone toinadvertent failure due to unwanted disconnection of the needle from therubber septum. Moreover, repeated piercing of the coupler with theneedle can taint the sterile fluid pathway.

The prior art has attempted to address the foregoing concerns byemploying needleless systems and locking connectors, but they too aredesigned as universal connectors which are subject to route ofadministration errors. For example, a patient may be connected tomultiple fluid delivering devices, hence forming multiple fluidpathways. The medical connectors are typically coupled to fluiddelivering and receiving devices by universal type connectors, such asluer fittings. Hence, an attending person may accidentally apply amedicament to the wrong fluid pathway since the universal connectoraccepts or can be coupled to conventional fluid delivering devices.

It is an object of this invention to develop a needleless, relativelysafe, locking connector system that is fluid path-specific. That is, thesystem should allow only infusions or injections of the proper type tobe connected to the specific catheter or tubing type. In order tomaintain efficiency and ease of locating the proper connectors,especially in an emergency, the types of connectors should be easilydeterminable by inspection.

Other general and more specific objects of the invention will in part beobvious and will in part appear from the drawings and description whichfollow.

SUMMARY OF THE INVENTION

The invention described herein is designed to eliminate, prevent orreduce the occurrence of unwanted or accidental administration of fluidsto the wrong fluid pathway through known universal connectors. Thepresent invention addresses this problem by replacing the universalconnector with unique specially configured male/female connector pairs,each coded for use with only one type of medical catheter or device(e.g., peripheral intravenous catheter, central venous catheter,arterial catheter, epidural catheter, dialysis catheter).

The present invention specifically describes in one aspect a family ofmedical connectors designed to attach a medical infusion or injectiondevice to a patient catheter or device. It is comprised of pairs ofmale-female locking connectors. The mating surfaces are uniquely indexedso that only complementary halves of the appropriate set connecttogether. Preferably, the fluid path runs through the length of theconnector halves, with complementary shape- and/or size-indexed piecesconstructed coaxially with the fluid path in each half connector. Whenin use, the two halves are pressed together and via a number of possibletechniques locked into position, thus completing the fluid path. Theends of the connector halves opposite the mating surfaces can attach tostandard luer-type medical connectors, preferably female on one half andmale on the other, in order to interpose the mated connector between acatheter or other patient receiving device and an infusion or fluiddelivering device, such as an intravenous tubing set or a syringe. Incertain specialized applications, female-female, or male-male outer endscan be incorporated; in still others, non-luer fittings may beincorporated, for example to facilitate piercing a vial or intravenousfluid container.

According to another aspect of the invention, one half of the connectorcan be permanently attached to a catheter, infusion tubing set orsyringe. This facilitates use of the device in applications which areespecially sensitive to errors in fluid or medication administration, toensure correct drug administration in emergency situations. In anotheraspect, a valve can be incorporated into either or both halves of theconnector pair which closes the fluid path when the two halves are notmated together, or may incorporate irreversible locking mechanisms toattach the connector half permanently to a catheter, tubing end orsyringe.

The present invention also provides for a medical connector suitable foruse in coupling a fluid delivering conduit to a fluid receiving conduit,such as a catheter adapted for insertion within a patient. The medicalincludes first and second connector housing parts having a first endsized to mate with the fluid receiving and delivering conduits and asecond end having a selected first surface feature formed thereon. Whenassembled, the first surface feature of the first housing part coupleswith the second surface feature of the second housing part to form afluid connection therebetween.

The present invention further provides a locking mechanism for lockingthe medical connector to a fluid conduit. The locking mechanism mayinclude a ratchet mechanism that allows rotation of the medicalconnector about the fluid path in one direction only. As a result, oncethe medical connector has been attached to the fluid conduit, removal ofthe medical connector from the fluid conduit is difficult or impossible.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of theinvention will be apparent from the following description and apparentfrom the accompanying drawings, in which like reference characters referto the same parts throughout the different views. The drawingsillustrate principles of the invention and, although not to scale, showrelative dimensions.

FIG. 1 is a perspective view of one embodiment of a medical connector incorporating a selectively configured connection mechanism employing bothraised and recessed surface features according to the teachings of thepresent invention.

FIG. 2 is a perspective view of the medical connector of FIG. 1 disposedin a closed or assembled position.

FIG. 3 is an end view of the two half portion of a medical connectorillustrating another embodiment of the connection mechanism inaccordance with the teachings of the present invention.

FIG. 4 is an unassembled perspective view of another embodiment of themedical connector in accordance with the teachings of the presentinvention.

FIGS. 5A through 5D illustrate various constructions of the connectionmechanism in accordance with the teachings of the present invention.

FIGS. 6A through 6C illustrate various constructions of a lockingmechanism suitable for use with the medical connector of the presentinvention.

FIGS. 7A through 7D illustrate the manner in which the medical connectorof the present invention can be coupled to various fluid delivering orreceiving devices.

FIGS. 8A-8D illustrates the medical connector including a ratchetmechanism for locking the medical connector to a fluid conduit,illustrated as a syringe, according to one embodiment of the presentinvention.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

This present invention involves one or more, such as a family, ofmedical connectors with male and female halves which are shape- and/orsize-indexed so that only complementary pairs of connectors may becoupled and then employed to deliver a fluid a patient along a selectedfluid pathway. The connectors of the present invention help avoidaccidental administration of a fluid to the wrong fluid pathway byensuring that fluid delivering devices can only be connected to a fluidreceiving device having a specific configuration. The present inventionmay be adapted to many different medical applications in the field ofmedical connectors, injection apparatus, and infusion devices.

FIG. 1 shows a perspective view of two general medical connectorportions, designated as a first male medical connector portion 1 and asecond female medical connector portion 3, which incorporate in theirfirst ends, respectively, a protuberance 15 and a cavity 25complementary in shape to the protuberance. These surface features allowthe two connector halves to fit together in a fluid-tight seal, as shownin FIG. 2. A fluid path runs through the long axis 4 of the firstportion 1 and the second portion 2. Specifically, the medical connectorportion 1 includes a central fluid lumen 10 that extends longitudinallytherethrough from one end to the other. Likewise, the other medicalconnector portion 3 includes a central fluid lumen 60 that passeslongitudinally therethrough. When assembled, the fluid lumens 10, 60 aredisposed in registration with one another to form an intermediate fluidpathway that connects a fluid delivering device to a fluid receivingdevice.

The illustrated first medical connector portion 1 has a surface featureformed on a mating end, such as the raised protuberance 15. Theprotuberance 15 can have many shapes, and as illustrated is an annulushaving an outer, flattened surface 5 that is disposed generallyperpendicular to the long axis 4 of the connector 1 and the lumen 10.The second medical connector 3 has a complementary shaped surfacefeature, such as recess or cavity 25, which seats the protuberance 15 ofthe first connector portion 1. The recess 25 ends in a floor stop 65which is designed to stop the advance of the protuberance 15 whendisposed within the recess. Central lumen 60 forms a second fluidpathway within the connector 3 and extends substantially from therecessed first end to the opposite end.

The matable complementary shaped surface features 15,25 of the medicalconnectors are designed to be incompatible with conventional typefittings, such as luer taper fittings, which are a family offriction-fit, locking connectors of standardized size and shape, widelyused in medical applications, and well known in the art. The surfacefeatures can have a variety of shape and sizes, such as illustrated inFIGS. 5A-5D.

The illustrated first medical connector 1 includes an outer housinghaving a recessed end which forms an outer annulus 26 that is coaxiallydisposed about the protuberance 15. The outer annulus 26 includes anumber of channels 28 formed therein, which terminate in a lock or keyportion 29, formed towards an intermediate portion of the medicalconnector. The medical connector 1 can further include a series ofcircumferential grooves 32 formed about the outer body portion of theconnector. The grooves are preferably sized to seat a locking arm, FIG.6C, that can be formed on the other medical connector part for lockingor securing the two connector components together to form a fluid-tightseal.

With further reference to FIG. 1, the medical connector portion 1further includes a stepped outwardly extending housing portion 34, and afurther outwardly extending portion 36 that extends along thelongitudinal axis 4. This portion terminates in a flange or collar 55adapted to connect with a fluid receiving or delivering device. Theother medical connector part 3 includes an outer housing portion 38configured complementary to the mating end 20 of the other connectorportion 1, so as to be able to couple thereto in a fluid sealingarrangement. Specifically, the outer housing portion 38 of the medicalconnector 3 terminates in a tab portion 35 that is designed to seatwithin the key portion 29 of the other medical connector portion 1. Theconnector 3 is further tapered at an intermediate portion 42 andincludes a cut-out portion 44. The connector terminates in a chamferedend 70 having an axially extending connector 50.

The two medical connector portions 1, 3 when mated together can eitherbe held together, by a friction fit arrangement, by the key lockingscheme illustrated in FIG. 1, or by a number of other locking schemes,as shown in FIGS. 6A through 6C. The illustrated locking scheme involvesseating the protuberance 15 in the recess 25 such that the matingportions of the two connectors are coaxially arranged. Furthermore, theouter housing 38 of connector 3 has an end 30 that seats within thespace or channel 31 formed between the protuberance 15 and the outerannulus 26. Likewise, the outer end 20 of the protuberance is coaxiallyarranged with and seats about the outer surface or shell 38. In order toassemble the connector parts, the portions 1 and 3 are pressed together,and the outer housing portions rotated around its long axis so that thetab 35 engages and locks with the complementary key portion 29. Theassembled medical connector portions form a secure, fluid-tight medicalconnector 40 that couple together various fluid devices, such ascatheters, needles, or syringes connected to the luer fittings 55 and50, as illustrated in FIG. 2.

The illustrated medical connector portions 1, 3 of the invention aredesigned to be application or path-specific. The male or first connectorportion 1 of the medical connector 40 is configured to mate with onlyone type of mating surface, although selected others are alsocontemplated, and will not mate with other female type connectors. Thusa connector designated, for example, for epidural catheter injections isgenerally incapable of connection to a syringe intended for intravenousinjection absent the specially configured surface feature. The identityof the connector type is readily recognizable by the skilled artisanfrom the shape or design of the mating surfaces, as well as fromdistinctive markings on the outer surfaces of the half connectors. Thesemarkings can include textured features, color coding and/or text labels,such as labels 70.

Each medical connector portion 1, 3 has an end 55, 50 opposite themating surface or ends 20, 30 that are adapted to mate to a fluiddelivering device, such as catheters, needles, syringes or other medicaldevices. In the illustrated connector of FIG. 1, the ends 55, 50 can bestandard luer taper fittings, either slip or locking type, which areeasily connected to the fluid delivering or receiving devices. Luer typefittings are well known and well characterized, and need not bedescribed further herein. The use of safe and secure luer-type fluidfittings allow the safety medical connector 40 to be interposed betweenstandard medical components now in widespread use. The medical connector40 can also be permanently incorporated into various catheters,connectors, syringes, tubing sets, and other devices designed forpatient connection, as shown in FIGS. 7A-7D.

FIG. 3 illustrates another type of connector design suitable for use inaccordance with the present invention. The illustrated connectorincludes two connector portions 60, 62 designed to join together to forma fluid-tight seal for the injection or infusion of a medication ormedical fluid, or alternatively for the evacuation of a body fluid, viaa catheter or device placed into the patient's vein, artery, epidural orspinal space, or other body compartment. The medical connector portions60 includes a quadrilateral shaped raised surface feature 66 extendingfrom one end 60A. The connector includes a fluid lumen 68 formed thereinthat extends between the connector ends. The other connector portion 62has a recessed surface feature 72 complementary in shape to the raisedfeature in order to accommodate and properly seat the raised feature toform a fluid tight seal. According to one practice, the end region 62Aincludes a cavity 72 that has a floor portion 74. The floor portion isapertured with an opening that defines the fluid lumen 70. The lumenextends between the connector ends.

When assembled, the protuberance 66 seats within the cavity 72 todispose the lumen 68 in fluid communication with the lumen 70 to form acontinuous fluid path along the assembled connector and between, forexample, an infusion or injection source and a patient catheter. The twoconnector portions 60, 62 can be locked together using a variety ofdifferent schemes as discussed below. The locked pair of medicalconnector portions can include additional connection sites (such as luerfittings) on the ends opposite the mating surfaces 60A, 62A which allowthe device to be inserted between the patient and the injection,infusion, or evacuation source. For example, the basic design canconsist of standard luer taper fittings attached to each medicalconnector half. Therefore, an epidural catheter 80 can be connected viaits female luer hub adapter 82 to a male luer fitting 84 coupled to oneend of a medical connector, generally illustrated as medical connectorportion 86, configured in accordance with the present invention. Theconnector 86 couples to the other connector half to complete the medicalconnection. According to one practice, the illustrated connector 86,when not coupled to its mating connector, generally cannot be connectedto any standard syringe or medical tubing which is devoid of acomplementary surface feature.

FIGS. 5A through 5D illustrate still other embodiments of the surfacefeatures which can be formed on the mating ends of the medicalconnectors in accordance with the present invention. In each case, acomplementary pair of protuberances and recesses are incorporated intothe medical connectors. In FIG. 5A, the protuberances can have a varietyof geometric shapes, which are arranged coaxially around the lumen 10.The shapes of the surface features can further include a triangle 100,square 105, pentagon 110, hexagon 115, or other regular polygon orquadrilateral shape. As is readily apparent to those of ordinary skill,each illustrated surface feature can replace the cylindricalprotuberance 15 of FIG. 1. The raised surface features fit into acomplementary shaped and sized cavity formed in the other medicalconnector half.

FIGS. 5B and 5C illustrate employing raised surface features that havevarying sizes. In these instances, the lumen 10 is surrounded by acylindrical protuberance of small 130, intermediate 135, or larger 140diameter, or alternatively a regular polygon of small 145, intermediate150, or larger 155 size. FIG. 5D illustrates employing radialprojections in an outer surface of the connector half, to effectuateradial pin indexing. In this configuration, radially spaced pins 160 arearranged circumferentially about the protuberance 15. These pinsuniquely mate with complementary slots 165 arranged radially within thewalls of the cavity 25 formed in the other connector half.

The foregoing medical connectors can be fashioned from hard plastic orother suitably minimally deformable material, so that incompatibleconnector halves cannot mate in a fluid-tight manner. Attempts to do sowill cause the fluid path to leak, preventing inadvertent injection.Integrity of the fluid path can be ensured either by a tight frictionfit between the complementary connector parts, or by the inclusion of anintegral rubber or other deformable gasket on the male portion of theconnector pair. This gasket would be slightly larger in its non-deformedstate than the complementary female half connector's cavity, so thatwhen the two connectors are mated, the gasket deforms and causes a tightseal.

Two complementary medical connector portions can be joined together toform a complete medical connector. Once assembled, the connectorportions can be locked into the mated or joined position in a variety ofways. Some examples of locking arrangements suitable for use with themedical connector of the present invention are illustrated in FIGS. 1and 6A through 6C. As described above, the connector portions 1 and 3 ofFIG. 1 include a key and tab engagement arrangement to secure theconnector halves together. FIG. 6A illustrates a pair of medicalconnectors 200 and 205 which can be assembled and held together with asimple friction fit. In this configuration, the mating portion ofconnector 200 is slightly smaller-in size than the complementaryconnector 205 so that when engaged, sufficient force is required toseparate the connector pair such that ordinary injection pressures donot separate them. Specifically, the medical connectors 200, 205 requiresome amount of force to separate the connector portions. The tolerancesof the two mating medical connector portions are such that the pressurein the fluid delivering or receiving conduits attached to the connectorare generally insufficient to drive the pair apart.

FIG. 6B illustrates another of securing or locking the connectors 300and 320 together. In this embodiment, the connector 300 includes astepped axially extending lip portion 305 formed on the mating end ofthe connector. The lip of the larger connector includes a slightlyraised portion or detent 306 extending radially inwardly towards or intothe lumen. The lip 305 is adapted for engagement with a complementarychannel or indent formed in the mating end of the other connector 320,which is of slightly smaller diameter. The two connector halves can locktogether with a pushing action, with one side designed to pass over theother. When assembled, the smaller connector 320 is pushed within thelarger connector half 300 until the lip 305 engages the complementaryindent 310, thereby securing the connector portions together.

FIG. 6C shows the similar arrangement of two outer housings of slightlydifferent diameters 300 and 320 with slots 400 formed on the outersurface of connector 320, which engage slightly spreadable or deformablefingers 405 attached to and extending from the other connector half.

Still other embodiments of securing mechanisms include providingconnector portions that contain a central fluid lumen, and ending inluer or other fittings for connection to medical tubing, syringes, orcatheters. The entire inner portion of the connector is adapted to spinfreely around the axis of the fluid lumen. When assembling together thetwo medical connector halves, the inner portions of the connectors matetogether, and then the outer housing portions of the connectors aretwisted together to lock them. Several mechanisms for locking the outerportions are possible. The two outer housings could be designed withcomplementary deformable tabs and slots which engage when twistedtogether, threaded ends which screw together, or fingers on one partwhich lock into slots on the other part, as described above inconnection with FIGS. 6A through 6C. Another embodiment of a securingmechanism can include configuring the inner mating portions of theconnector portions so as not to spin along the axis of the fluid lumen.

As described above, the foregoing medical connectors function as a basicinterface between standard fluid delivering and receiving devices, suchas standard catheters and infection sources, via standard medical luerfittings. In the usual application, one connector portion of the presentinvention contains at its non-mating end a male luer fitting with orwithout a standard twist-lock feature, and the other connector containsa similarly positioned female luer fitting. In certain specializedapplications, twin female or male luer adapters could be incorporated.

This medical connectors of the invention can also be fitted withconnectors at the non-mating ends that allow its connection to othermedical devices and containers. In one important embodiment of thisinvention, one connector half is permanently fused to or incorporatedinto a standard medical infusion device, so that use of a complementaryconnector is mandatory to access the catheter or device. For example, anepidural catheter adapter, which typically grips a 18 to 21 G epiduralcatheter and ends in a female luer fitting, is mounted to one end of themedical connector half. Only a syringe or tubing set incorporating orfitted with the complementary half connector can be used with this typeof epidural catheter. Any catheter, injection adapter, tubing set,syringe, or device connecting to a patient catheter and currently usingluer universal connectors can be adapted to incorporate half connectorsof a given type from the present invention. The invention thus allows afamily of safety injection sources and catheters to replace theinherently less safe universal connectors in wide use today.

The foregoing safety medical connectors are designed to be interposedbetween existing devices for medical infusions, injections, oraspirations. An additional feature of the present invention is thefusion of a half connector as illustrated in FIG. 1 into a standardmedical connector or device. FIGS. 7A through 7D illustrate theincorporation of a safety connector half into an epidural catheterconnector 500, which in turn is connected to an epidural catheter 505.Any of the mating and locking configurations of the present invention,for example the rectangular surface feature 510, can be incorporatedinto the end of the epidural catheter connector. The epidural catheterconnector in turn mates with a complementary safety connector half 520.This connector half includes a complementary shaped surface feature thatensures that only medications intended for epidural delivery areinjected through the epidural catheter, since only a specific surfacefeature 510 can mate with the connector half 520.

FIG. 7B illustrates another example of attachment mechanisms adapted foruse with the medical connector of the present invention. The illustratedmedical connector can be coupled to a hollow sharpened spike designedfor piercing bags of intravenous fluids, blood products, or premixedintravenous medications; a connector to feeding tubes; or a connectorfor certain specialized catheters used in peritoneal dialysis.Specifically, a half connector 1 is incorporated into a tubing set forinfusion of fluids or medications into a patient, typically comprised oftubing 540 and a spike 535 for piercing a container of fluid ormedication, which can be seen to be infusing through a transparent dripchamber 530. In still another configuration, as shown in FIG. 7C, a halfconnector 1 is incorporated into a syringe 545. In another embodiment,as shown in FIG. 7D, a half connector 1 is incorporated into a three-waystopcock 550 which allows entry of medication or withdrawal of fluids ormedications from a tubing set 555.

Other variations of the basic design of the medical connector of thepresent invention are contemplated by this invention and thus form partof the description. First, one medical connector half may be fusedpermanently or incorporated into an existing medical infusion orinjection device. For example, a syringe prefilled with a medicationthat can only be given safely by a certain route could be fashioned witha half connector on its end. Only by mating with a catheter fitted withthe appropriate complementary connector part (perhaps also permanentlymounted) can the injection be given. Tubing sets designed for particularapplications such as epidural anesthetic infusions can be fashioned withinjection sites which only connect to other complementary connectorparts. Thus, while allowing simple and needleless injection ofadditional medications, inadvertent injection of inappropriatemedications would be significantly less likely, and hence prevented.

According to another embodiment, shown in FIGS. 8a-8 d, the illustrativemedical connector may include a ratchet mechanism to lock the medicalconnector to a fluid conduit. As shown in FIGS. 8a, a syringe 546 orother fluid delivering device includes a medical fitting 548 havingscrew threads 547 for receiving the medical connector 1′. As shown inFIG. 8b, the medical connector includes protrusions, such as teeth 500 aand 500 b, formed on the outwardly extending portion 36′ that extendsalong the longitudinal axis. The teeth 500 a, 550 b screw into thethreads 547 of the syringe 546 to couple the medical connector to thesyringe 546.

As shown in FIGS. 8b and 8 c, the medical connector 1′ includes an outersleeve 560 and an inner body 561, which is integral with the outwardlyextending portion 36′ and includes the central fluid lumen 10′ passinglongitudinally therethrough. The outer sleeve 560 of the medicalconnector is adapted to spin about the inner body 561 in one directiononly, illustrated by the arrow. The outer sleeve 560 include teeth on aninner surface that mesh with a pawl of the inner body 561 to preventbackward motion of the outer sleeve 560. One skilled in the art willrecognize that any suitable mechanism for imparting, governing orpreventing motion of the outer sleeve 560 relative to the inner body 561in order to allow effective movement of the outer sleeve around theinner body in one direction only may be utilized.

When the medical connector 1′ is coupled to the syringe 546, as shown inFIGS. 8c and 8 d, unscrewing of the medical connector from the syringeis difficult or impossible. The medical connector 1′ is locked to thesyringe 546 by inserting the outwardly extending portion 36′ into themedical fitting 548 and rotating the medical connector in a seconddirection opposite the direction of the arrow. When the medicalconnector is rotated in the second direction, relative motion betweenthe outer sleeve 560 and the inner body 561 is prevented by the ratchetmechanism and the outer sleeve 560 and the inner body 561 rotatetogether as one collective body. The teeth 500 a, 500 b of the medicalconnector 1′ engage the threads 547 of the fitting and follow the rampededge of the threads until the medical connector 1′ is tightly secured tothe syringe 546. However, when a user attempts to unscrew the medicalconnector 1′ from the syringe 546 by rotating the medical connectorabout the longitudinal direction in the direction of the arrow (i.e.opposite the direction in which the medical connector was rotated toscrew the medical connector to the syringe), the outer sleeve 560rotates without turning inner body 561, extending portion 36′ and teeth500 a, 550 b. The teeth 500 a, 500 b remain lodged in the threads 547 ofthe fitting 548 and the medical connector 1′ remains locked to themedical fitting 548. The relative movement of the outer sleeve 560 whilethe inner body 561 remains fixed thus prevents or impedes unscrewing ofthe medical connector from the syringe.

The illustrative medical connector 1′ modifies the interface of thesyringe 546, such that the syringe 546 can only mate with and form afluid tight seal with a fluid conduit having a corresponding medicalconnector 3′, shown in FIG. 8d, coupled thereto. According to theembodiment shown in FIGS. 8a through 8 d, the first medical connector 1′includes slots 165′ for receiving radially spaced pins 160′ on thesecond medical connector 3′. The outer sleeve 561 includes internalthreads 570 for receiving the pins 160′ of the corresponding connector3′. The central fluid lumen 10′ of the first medical connector portion1′ extends longitudinally therethrough from one end to the other.Likewise, the complementary medical connector portion 3′ includes acentral fluid lumen 60′ that passes longitudinally therethrough and isadapted to receive the protruding central fluid lumen 10′ of the firstconnector portion 1′. To couple the medical connectors, the pins 160′are inserted into the complementary slots 165′ and screwed into thethreads 570, such that the first central fluid lumen 10′ is insertedinto the second central fluid lumen 60′. The assembled medicalconnector, comprising the first medical connector 1′ and the secondmedical connector 3′ thus forms a continuous fluid path that sealinglyconnects the syringe 546 and a fluid receiving device (not shown) thatis connected to the second medical connector 3′.

In other designs, either or both medical connector portions can befitted with a valve which is disposed in a normally closed position butis opened by appropriate mating with a complementary connector. A springloaded mechanism closes the valve whenever the connector parts aredisconnected, preventing fluid leaks and contamination of the lumen. Theconnector portions can also be configured to connect to standard medicalinfusion devices or catheters via essentially irreversible mechanisms sothat, once connected, the safety of the device cannot be subverted byremoving one half connector to restore a universal connection. Anexample of such an application is the preservation of one lumen of acentral venous catheter exclusively for infusion of parenteral nutritionsolutions. Commonly, warning labels or adhesive tape are placed over therubber septum cap on the end of such a port, but these are easilysubverted. A locked half connector from the present invention would allbut eliminate this problem. Two such methods for locking the connectorsare as follows. First, a modified screw-type male luer adapter with awedge shaped enlargement incorporated into the screw threads may besubstituted for an ordinary male luer adapter. A tab on thecircumferential edge of a standard female luer adapter normally engagesthe threads in the male screw-type luer connector. When it meets thewedge in the threads of the modified adapter described here, it followsthe ramped edge of the wedge, slightly deforming the threaded connectoruntil it crosses the end of the wedge and returns to the threaded path.Because the wedge is placed so that the narrow end is contacted firstduring clockwise (tightening) rotation of the male luer adapter,unscrewing of the adapter once the wedge has been passed will be verydifficult or impossible.

A second method for locking the present invention to an existing femaleluer adapter is to dispose a coaxial collar about the adapter. The innermale screw adapter is of standard design, and an outer collar is adaptedto spin about its long axis (which includes the fluid path). Teetharranged in the space between the male luer screw portion and the outercollar allow the outer collar to turn the inner male luer screw fittingonly in the clockwise direction. Counterclockwise rotation is impossiblebecause the teeth do not engage, and therefore once the modified maleluer adapter has been screwed onto the female luer adapter, unscrewingthem is difficult or impossible.

Still another modification of the connector of the invention is a familyof accessory caps for covering the unmated half connectors of the basicdevice or its modifications as described elsewhere in this section.These caps have inner surfaces complementary to the male or femaleconnector halves and insert over the mating surface of the connectorhalf, preferably with a friction-fit.

This invention is designed to be used in both routine and emergencymedical care. As such, simple and rapid identification of thecomplementary half connectors is important. Besides inspection of themating surfaces themselves, a variety of techniques may be utilized toease identification of the connectors (see Section 5). The preferredimplementation of this technology into medical practice would involvestandardization of the various connector types to be used only forcertain catheters. For example, there could be one type only used forepidural catheters, one for peripheral intravenous catheters, andanother for central venous catheters.

In certain applications, the medical connectors of the present inventionmay be advantageously employed with indwelling lines, i.e., central andperipheral intravenous lines, to offer selectivity relative to the fluiddelivering device. For example, a syringe filled with a medicament thatcan be safely administered both peripherally and centrally, such asmorphine, should be able to mate, via the medical connectors of thepresent invention, with the central and peripheral intravenous lines. Inthis embodiment, a pair of first housing parts having the same surfacefeature are coupled to both fluid receiving or indwelling pathways. Thesyringe (fluid delivering device) has coupled thereto a connector halfthat has a shape complementary to the shape of the other surfacefeature, thus enabling this connector and syringe to couple to bothfluid pathways, and nothing else, if desired. However, a medicament thatis not safely administered peripherally, such as potassium chloride, canbe pre-filled in a syringe that could mate only with the connector halfassociated with the central line. Hence, the central intravenous line orpathway mates with both the central and peripheral compatible syringes,but the peripheral line connector only mates with the peripheralsyringe. The central and peripheral lines can be manufactured with suchfittings as integral parts, or as irreversibly attachable connectorswhen site specificity is warranted.

The general concept embodied in this technology, in summary, is thatmedical connectors are made path-specific rather than universal. Thisgeneral description is of a pair of connectors disposed between standardfluid delivering and receiving devices.

It will thus be seen that the invention efficiently attains the objectsset forth above, among those made apparent from the precedingdescription. Since certain changes may be made in the aboveconstructions without departing from the scope of the invention, it isintended that all matter contained in the above description or shown inthe accompanying drawings be interpreted as illustrative and not in alimiting sense.

It is also to be understood that the following claims are to cover allgeneric and specific features of the invention described herein, and allstatements of the scope of the invention which, as a matter of language,might be said to fall therebetween.

Having described the invention, what is claimed as new and desired to besecured by Letters Patent is:
 1. A medical connector suitable for use incoupling a fluid delivering conduit to a fluid receiving conduit foradministering fluid to a patient, said medical connector comprising: afirst medical connector housing part having a first end sized to matewith a first medical fitting on one of said fluid receiving conduit andsaid fluid delivering conduit and a second end having a selected firstsurface feature formed thereon, second medical connector housing parthaving a first end configured to mate with a second medical fitting onthe other one of said fluid receiving conduit and said fluid deliveringconduit, and a second end having a selected second surface featurecomplementary in shape to the first surface feature of the first housingpart, so that when assembled the first surface feature of the firsthousing part couples with the second surface feature of the secondhousing part to form a fluid connection therebetween, and a lockingmechanism for locking together said first medical connector housing partand said first medical fitting, comprising a protrusion on the first endof the first medical housing part and screw threads on said firstmedical fitting adapted to receive the protrusion, wherein said firstsurface feature is sized and configured so as to only mate with thecomplementary shaped second surface feature to prevent another fluiddelivering conduit associated with a differently configured surfacefeature from being connected to the fluid receiving conduit, therebypreventing the accidental administration of another fluid to the patientthrough the first and second housing parts.
 2. The medical connector ofclaim 1, wherein the first medical connector housing part comprises: aninner body rigidly connected to the protrusion and containing a centralfluid lumen; and an outer sleeve surrounding the inner body andconfigured to rotate in a first direction about the inner body.
 3. Themedical connector of claim 2, wherein the first medical connectorhousing part further includes a ratchet mechanism to prevent rotation ofthe outer sleeve in a second direction opposite the first direction. 4.The medical connector of claim 3, wherein the ratchet mechanismcomprises teeth on an inner surface of the outer sleeve engaging a pawlformed on an outer surface of the inner body.
 5. The medical connectorof claim 3, wherein the first medical connector housing part is lockedto the first medical fitting by inserting the protrusion into thethreads and rotating the medical connector in the second direction suchthat the protrusion engages the threads, thereby screwing the firstmedical connector housing part into the first medical fitting.
 6. Themedical connector of claim 5, wherein rotation of the first medicalconnector housing part in the first direction causes the outer sleeve torotate about the inner body while the protrusion is maintained in anengaged position with the threads.
 7. A method of administering fluid toa patient, comprising providing a first medical fitting coupled to adistal end of one of a fluid receiving conduit and a fluid deliveringconduit, said first medical fitting including screw threads; locking afirst medical connector housing part to said first medical fitting,wherein said fist medical connector housing part has a first end havinga protrusion adapted to mate with the screw threads of the first medicalfitting, and a second end having a selected first surface feature formedthereon, providing a second medical fitting coupled to a distal end ofthe other of the fluid delivering conduit and the fluid receivingconduit, attaching a second medical connector housing part to saidsecond medical fitting, wherein said second medical connector housingpart has a first end adapted to mate with the second medical fitting, asecond end having a selected second surface feature complementary inshape to the first surface feature of the first housing part, andconnecting said first medical connector housing part to said secondmedical connector housing pan so that when assembled the first surfacefeature of the first housing part couples with the second surfacefeature of the second housing part form a dedicated fluid path from afluid source to the patient, wherein said first surface feature is sizedand configured so as to only mate with the complementary shaped secondsurface feature to prevent another fluid delivering conduit associatedwith a differently configured surface feature from being connected tothe fluid receiving conduit and wherein one of the first and secondmedical connector housing parts includes a set of valves to preventfluid flow through the dedicated fluid path unless the first housingpart is properly mated with the second housing part, thereby preventingthe accidental administration of another fluid to the patient throughthe first and second housing parts.
 8. The method of claim 7, whereinthe first medical connector housing part comprises: an inner bodyrigidly connected to the protrusion and containing a central fluidlumen; and an outer sleeve surrounding the inner body and configured torotate in a first direction about the inner body.
 9. The method of claim8, wherein the first medical connector housing part further includes aratchet mechanism to prevent rotation of the outer sleeve in a seconddirection opposite the first direction.
 10. The medical connector ofclaim 9, wherein the ratchet mechanism comprises teeth on an innersurface of the outer sleeve engaging a pawl formed on an outer surfaceof the inner body.
 11. The medical connector of claim 9, wherein thefirst medical connector housing part is locked to the first medicalfitting by inserting the protrusion into the threads and rotating themedical connector in the second direction such that the protrusionengages the threads, thereby screwing the first medical connectorhousing part into the first medical fitting.
 12. The medical connectorof claim 11, wherein rotation of the first medical connector housingpart in the first direction causes the outer sleeve to rotate about theinner body while the protrusion is maintained in an engaged positionwith the threads.